It is highly desirable to provide vehicles with signaling devices by which drivers of adjacent vehicles can be made aware of another driver's intentions and actions. The desirability of supplementing visual indicator signals provided by vehicle tail lights has manifested itself in a Federal Motor Vehicle Safety Standard requiring cars to have a center high-mounted stop lamp (CHMSL) placed in the rear of the vehicle at a point higher than that normally associated with tail lights.
Additional supplements to the brake signals as well as turn indicators and four-way flashers, are seen as being potentially beneficial as a warning device to operators of adjacent vehicles. One difficulty of providing such a signaling feature, however, is that mounting such a signaling device to the sides of the vehicle would detract from the vehicle's appearance, as well as potentially causing secondary problems such as wind noise. The present invention provides such a signaling device which is concealed within the existing envelope of the vehicle by locating them inside the exterior rearview mirror housings.
U.S. Pat. No. 5,014,167 to Roberts describes a signaling device so concealed. However, it relied on a light baffle to prevent the signaling device from interfering with the driver's use of the mirror. The baffle is an inefficient transmitter of light requiring a relatively high powered light source to produce a signal sufficiently bright to be seen by drivers of adjacent vehicles. The use of a high power light source creates heat distribution problems within the mirror housing. The present invention teaches how to provide a clearly visible signal with a light source of much lower power.